The landlady seized my lead instantly. “It was the right hand shutter,” she said, “in the very window you’re looking out of now.” I bent eagerly to look at the hinges. They were brand new, while those on the other side were strained and worn through years of exposure to wind and sun and rain. “You don’t say,” I replied. “Most interesting. I suppose the hinges rusted and broke.” “No,” said the landlady, “that was one of the queerest things about it. After the whole thing was over, and I came to look at the place where the shutter fell, there was no trace of a hinge. It must have pulled right out of the brick, and when I went next day to look at the shutters in the kitchen, the hinges, screws, and everything were gone, and I never saw the least trace of them from that day to this. We had the new shutter put up a week later.” “What luck!” I thought to myself, as I looked around over the adjoining housetops. “Hit it first time trying. Somewhere, behind those roofs, lies the laboratory of the man who is trying to stop all war.” I parted with the landlady, promising an early decision, and went in search of Tom and Dorothy. They left the carriage as I approached and hurried towards me. “The iron of the shutter disappeared,” I said significantly. Tom gave the long, low whistle which always typified interest and surprise to him. “You think the man’s laboratory is somewhere near here, then,” asked Dorothy excitedly. “Judging by Hamerly’s experience with the sign opposite Dr. Heidenmuller’s laboratory, I certainly do,” I answered seriously. “This probably happened just as that did.” “Then,” said Tom, “it’s probably up to us to make a house to house canvass of the neighborhood. It looks to me as if the chances were better in one of the buildings on Tottenham Court Road than in any of the houses round here.” “That’s right,” I answered briefly. “Tell you what we’ll do. We’ll ask at every shop if they know of any chemical laboratory. Tell ’em we’re hunting for a man who works in such a laboratory. Lay it on thick and give ’em plenty of detail. That’s the way to get the information you want.” “I’ll wait for you in the carriage round the corner,” Dorothy called after us, as we started away. From bakeshop to dairy, from furniture store to shoe shop, I travelled, searching for some news of my poor Cousin George, who had worked in a laboratory somewhere near the corner of Tottenham Court Road and Gower Street, and who had disappeared. Persistently diplomatic, I forced my way on, under rebuff after rebuff, leaving no store until I had a pretty vivid idea of the various occupations which made their home on every floor of its building. As I left after receiving one particularly stinging answer, I caught sight of Tom across the street, beckoning. I followed him at a little distance until he turned a sharp corner into a little alley. He appeared slightly dishevelled as he turned around.